Drill bit



" Dec. 24, 1935.

u. s. RUSH 2,025,476

DRILL BIT Filed April 22, 1950 I ZZ/ywe; yms/.

INVENTOR 1.7g V BY M ZQYL ATTORN EY Patented Dec. 24, 1935 10 various parts of the bit cooperate to compensate for wear. The cutters are firmly held in the bit in a manner to absorb, distribute and cushion the shock incidental to drilling and to preserve their alignment thereby producing a bit which is less subject to breakage, which will hold their cutting edges longer and therefore out faster and which will drill a hole which is not fissured or rifled.

These several objects are accomplished by means of a preferred form of my bit disclosed in 29 the drawing forming a part of the present specification but I do "not limit myselfto such form since my invention expressed in this specification may be embodied in a plurality of forms.

In said drawing like characters of reference are used to designate similar parts throughout the said specification and drawing and in which:-

Plg. 1 is a plan of the cutting face of my bit.

Fig. 2 is a view in side elevation of my bit.

Fig. 3 is a vertical sectional view through the center of the central cutting member 3, trans versely of its cutting edges 2-2.

Referring to the drawing, Fig. 1, numeral l-I, designates the cutting edges of the arcuated 35 cutting heads e-s, L4, and a a, 9-9. The

dotted lines on the arcuated cutting heads between 8-6 and l-l, and between 8-8 and 9-9, indicate the outline of the grooves and ridges on the sides of the shanks Ill, and sockets l2, and

also a longitudinal tapering of said shanks and sockets.

In Figs. 1 and 3, the cutting head of the central cutting member is indicated by 3-3, and the cutting edge by 2-2.

45 In Figs. 1 and 3, numerals 5-5 indicate the lower portion of the cutting head 3-3 of the central cutting member. Said lower portion 5-5 occupies the space as indicated in Figs. 1 and 3 between the two opposing vertical faces of the cutting heads -1 and s-a. In each of said opposing vertical faces is a vertical circular groove l-l5, Fig. 1. Each of said grooves li-li is occupied by a vertical circular ridge located on each of the two sides of said lower 55 portion 5-5 of the cutting head 3-: of the cenhe arcuated ciitt," BI-Q- t'ire therebS 10" lied in 2; numeral; show e cutting heads which-carry he erti 2 r m:-:. P a. Shank l, Figs. 1 and 3, starts as a vertical circular ridge on each of the two vertical sides of the lower portion 5-5 of the central cutting head 10 3-3 and occupies the vertical circular grooves l5-l5. From the bottom of 5-5 downwardly shank 4 is cylindrical and occupies an enlarged erki . portion of fluid passage M.

Fig. 2 is a view in side elevation of my bit in 16 which l-I-l indicate the arcuated cutting edges and 6-6, l-l, and 8-8, 9-9, indicate the arcuated cutting heads. Their compressible shanks l8 taper longitudinally toward their central slot l I from the larger end 6-6 of the cutting head to 20 the smaller end I-l. Likewise the shank H! of the opposite cutting head tapers from the larger end, 8-8 to the smaller end 9-9.

In Fig. 2 the longitudinally tapering socket of the shank I0 is indicated by numeral [2 which tapers with the shank l0. I3 is a longitudinal expansion slot in the bottom of the socket I2. If greater resilience is desired an expansion slot may be placed near each side in the bottom of socket l2. H is a compression slot extending the length and width of the shank 10. Both of 'said slots II and 13 may be packed with any suitable resilient substance to keep out mud or water if desired.

The spring hooks I'l, Fig. 3, are suitably fastened to the inside of shank 4 of the central cutter 3-3 and engage notches I8 on either side of the inside walls of fluid passage l4. They hold the central cutter in working position.

Numeral lG-IG, Figs. 1 and 3 is the bedy io I which carries the fluid passage and in the end of said body the sockets are formed.

Said body, numeral iii-l6, may be permanently or detachably aflixed as desired to a drill stock or other suitable holder or carrier;

I claim as my invention: v

1. In a drill bit of the class described, comprising a stock having transversely aflixed sockets at one end, said sockets being longitudinally transverse to said stock and expansible, slotted and longitudinally tapering and suitable for holding the compressible, slotted and longitudinally tapering shanks of separately detachable cutting members, the other end of said stock fastened as desired to any suitable holding means, a fluid p'as- I sage centrally located in said stock and bit, the outer end of. said fluid passage enlarged to form a central socket for the shank of a central and separately detachable cutting member, transversely expansible slotted sockets, longitudinally tapering and oppositely disposed on either side oi. said central cutting member and having longitudinal wear and shock absorbing and distributing holding grooves and ridges on their sides, said grooves and ridges closely meshing with like grooves and ridges on the sides 01' the transversely compressible and longitudinally tapering and slotted shanks of separately detachable cutting members each comprising a cutting edge, a cutting head and the aforesaid compressible, slotted and tapering shank extending downwardly from the under side of said cutting head and longitudinally therewith, said cutting head having longitudinal holding grooves on its underside oppositely disposed to either and extending longitudinally therewith to hold the upperedges of the aforesaid longitudinal and expansible sockets into which said longitudinal and compressible shank is driven and to absorb and distribute shock and wear on each 01' said detachable cutting members.

2. a drill bit 01 the class described comprising side of said shank a stock having transversely aflixed sockets at one end, said sockets being slotted, expansible and longitudinally tapering for holding the longitudi nally tapering -and transversely compressible shanks or separately detachable cutting members, the other end of said stock fastened as desired to any suitable holding means, a fluid passage centrally located in said stock and bit, the outer end of said fluid passage enlarged to form a central socket for the hollow shank of a separately detachable central cutting member, said hollow shank extending into and non-rozatively and decentral socket, two oppositely disposed spring hooks fastened to the inside or said hollow shank engage notches in the inside walls 01' said fluid passage. and hold said hollow shank 0! said central cutting member in place, the outer end or said hollow shank terminating in two cutting heads with their cutting edges in alignment transversely to said fluid passage and oppositely disposed and in alignment on either side thereof, locking means on the hollow shalt means on said oppositely disposed and separately working position,

ULY88EB SAMUEL RUSH.

.longitudinal cutting members locking them in as 

